Question

The average marks of 80 students were found to be 40. Later, it was discovered that a score of 54 was misread as 84 . Find the corrected mean of the 80 students

Answer 1

Answer:

38 .275

Step-by-step explanation:

Average of 80 students = total marks/40

total marks= average * 80

= 40*80

=3200

now let's remove the wrong number from the sum of total marks.

3200-84 = 3116

now let's add the correct number in the sum of total marks

3116-54 = 3062

so, correct sum of total marks= 3062

average= 3062/80

= 38 + 11/40

= 38.275

Answer 2

Answer:

The correct average of 80 students is 39.625.

Given:

Average marks of 80 students = 40

Later, it was discovered that a score of 54 was misread as 84

To Find:

Find the corrected mean of the 80 students

Step-by-step explanation:

Initially , Average marks of 80 students = 40

So sum of the marks of 80 students = 40x80

3200

Later, it was discovered that a score of 54 was misread as 84

So we have to remove 84 and add 54 to the sum of the marks of the students.

So the correct sum = 3200 -84 +54

correct sum =3170

So the correct average = new average / 80

correct average = 3170/80

=39.625

Hence the correct average of 80 students is 39.625.